FIELD ADJUSTABLE GAS BLEED ASSEMBLIES FOR USE WITH FIREARMS

Abstract

Field adjustable gas bleed assemblies for use with firearms are described. An example field adjustable gas bleed assembly for use with a firearm having a barrel includes a gas cylinder that defines a pressure chamber to be fluidly coupled to a bore of a barrel, wherein the gas cylinder is substantially fixed relative to the barrel. Additionally, the example field adjustable gas bleed assembly includes a fluid control apparatus to control a flow rate of fluid between the pressure chamber and the barrel. The fluid control apparatus is adjustable between a first operation mode and a second operation mode that is different from the first operation mode. The fluid control apparatus includes a first borehole having a first cross-sectional area. The first borehole is associated with the first operation mode. Additionally, the fluid control apparatus includes a second borehole having a second cross-sectional area different from the first cross-sectional area. The second borehole is associated with a second operation mode.

Description

RELATED APPLICATION

This patent is a continuation of International Patent Application Serial No. PCT/EP2007/006780, filed on Jul. 31, 2007, which claims priority to German Patent Application 10 2006 036 309.4, filed on Aug. 3, 2006, and to German Patent Application 10 2006 056 130.9, filed on Nov. 28, 2006, each of which are hereby incorporated herein by reference in their entireties.

FIELD OF THE DISCLOSURE

This patent relates generally to firearms and, more specifically, to field adjustable gas bleed assemblies for use with firearms.

BACKGROUND

Typically, gas-operated firearms include a loading mechanism that is driven by ammunition gas pressure acting against a gas piston arranged in a gas cylinder to assist in loading and unloading cartridges. The gas cylinder is at least partially sealed at an end so that a pressure chamber is formed between a face of the gas piston and a front wall of the gas cylinder. A passage fluidly couples the pressure chamber to the interior of the barrel. After a round is fired and the projectile (e.g., the bullet) has passed the connecting point between the pressure chamber and the barrel bore, ammunition gases enter the pressure chamber. The ammunition gases increase a pressure in the pressure chamber and create a resulting force on the face of the piston.

The resulting force on the piston acts against a linkage that is part of a loading mechanism and causes the cartridges to feed and eject due to the movement of the piston relative to the pressure chamber. Additionally, the resulting force on the piston activates (e.g., cocks) the trigger mechanism. When firing a firearm that is fully automatic, each time a cartridge passes the connecting point, a portion of the ammunition gases are diverted through the passage and toward the pressure chamber to act against the piston and, thus, load and unload the firearm. As a result, the cartridges are continuously loaded and unloaded as long as the trigger is held in the firing position and the firearm is provided with ammunition. DE 196 15 181 describes a known gas-operated firearm arrangement.

Typically, the cross-sections governing the flow of the ammunition gasses and the design of the gas piston and the pressure chamber are configured to match the specifications of a particular firearm that fires at a determined frequency. Specifically, a firing cadence is selected to prevent overstress of firearm components. To control the pressure in the pressure chamber, the pressure chamber is provided with a gas outlet axially positioned toward the front of the pressure chamber. Through the gas outlet, at least a portion of the ammunition gasses that enter the pressure chamber exit into the environment to reduce the pressure within the pressure chamber. Specifically, the pressure chamber has a lower pressure as compared to the pressure within the barrel. An example of such an ammunition gas bleed device is described in DE 19615 181.

DE 648 391 describes a gas-operated firearm in which ammunition gasses enter the pressure chamber from the front of the pressure chamber. To control the amount of ammunition gasses that enter the pressure chamber, the described gas-operated firearm is provided with a locking screw. In contrast to the gas-operated firearms described above, to exhaust the ammunition gasses from the pressure chamber, the piston moves entirely out of the cylinder to create a gap through which the ammunition gasses exhaust.

By making structural changes to a firearm and/or using different types of ammunition, the gas pressure in the barrel and/or the pressure chamber may change. For example, firing a firearm that is typically provided with a flash suppressor instead with a silencer, increases the pressure in the barrel and the pressure in the pressure chamber. The increase in pressure increases the force acting on the gas piston and accelerates the loading process, especially if the firearm is an automatic weapon. Similarly, if a second type of ammunition (e.g., ammunition having a larger propellant charge, a higher bullet mass, etc.) is fired through the firearm instead of a first type of ammunition (e.g., ammunition having a smaller propellant charge, a smaller bullet mass, etc.), the gas pressure in the barrel and/or the pressure chamber also changes, which effects the firing cadence.

Accelerating the loading process, increases the firing cadence as well as ammunition consumption. Additionally, the mechanical load on the firearm components increases the wear and tear on the firearm, which decreases the time interval between needed maintenance. Further, unnecessary consumption of ammunition may pose a logistical problem during a military action, because additional ammunition must be brought along and provided at the location that the firearm is being fired without the firearm's performance being correspondingly improved.

During military actions and/or training exercises, it is impractical to continuously adjust the ammunition gas bleed device in an attempt to stabilize the firing cadence.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a cross-sectional view of a portion of a barrel and an example field adjustable gas bleed assembly.

FIG. 2 depicts an enlarged cross-sectional view of a portion of the barrel and the example field adjustable gas bleed assembly of FIG. 1.

FIG. 3 depicts an enlarged side view of the barrel and the example field adjustable gas bleed assembly of FIG. 1.

FIG. 4 depicts an enlarged view of a different side of the barrel and the example field adjustable gas bleed assembly of FIG. 1.

FIG. 5 depicts another view of the example field adjustable gas bleed assembly of FIG. 1.

FIG. 6 depicts a cross-sectional view along A-A of FIG. 5 that depicts an example fluid control apparatus and an example locking member of FIG. 1.

FIG. 7 depicts the example fluid control apparatus of FIG. 1.

DETAILED DESCRIPTION

Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify the same or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity. Additionally, several examples have been described throughout this specification. Any features from any example may be included with, a replacement for, or otherwise combined with other features from other examples. Further, throughout this description, position designations such as “above,” “below,” “top,” “forward,” “rear,” “left,” “right,” etc. are referenced to a firearm held in a normal firing position (i.e., wherein the “shooting direction” is pointed away from the marksman in a generally horizontal direction) and from the point of view of the marksman. Furthermore, the normal firing position of the weapon is always assumed, i.e., the position in which the barrel runs along a horizontal axis.

FIG. 1 depicts a front portion of a firearm 100 having a barrel 1 that is coupled to a flash suppressor 2. The barrel 1 may be any type of barrel such as, for example, a barrel that includes grooves and lands or a barrel that has a smooth interior surface. The firearm 100 includes a field adjustable gas bleed assembly 3 (herein after referred to as gas bleed assembly 3) that is coupled to the barrel 1 via a locking mechanism (not shown) and/or rods (not shown).

Firing a round of ammunition propels a bullet from a cartridge casing through a barrel bore 4, which is concentric to a bore axis 6, toward the flash suppressor 2 in a direction of a target. Once the bullet has traveled past the gas bleed assembly 3, a portion of the ammunition gases enter a tap bore 8, which in the example of FIG. 1, is substantially perpendicular to the barrel bore 4. The portion of the ammunition gases flows from the tap bore 8 through a gas channel 10 into a pressure chamber 14 defined by a gas cylinder 12.

Turning now to FIG. 2, the illustration depicts an enlarged view of the barrel 1 and the gas bleed assembly 3. A piston 16 (e.g., a gas piston) is positioned in the gas cylinder 12. The piston 16 is sized to slidably and sealingly engage an interior surface 202 of the gas cylinder 12. The interior surface 202, the gas cylinder 12, and/or the piston 16 may be mechanically produced and/or finished via, for example, lathing, milling, grinding and/or honing (e.g., precision grinding). Additionally or alternatively, the interior surface 202, the gas cylinder 12, and/or the piston 16 may be treated using any suitable means such as, for example, the components may be hardened, chrome plated, coated, etc., to increase the durability of the contact surfaces. While not shown, the piston 16 may be provided with a plurality of rings (not shown) to provide a seal between the interior surface 202 and the piston 16.

After a round is fired, the ammunition gasses flow to the pressure chamber 14 and increase the pressure in the pressure chamber 14. Specifically, the pressure increases between a surface 204 of the piston 16 and a surface 206 of the pressure chamber 14. Once the pressure within the pressure chamber 14 increases to a predetermined level, a force, created by the pressure (e.g., a pressure impulse), moves the piston 16 toward the rear of the firearm 100 (FIG. 1) along with a rod (not shown). As the rod moves toward the rear of the firearm 100 (FIG. 1), the rod transfers the pressure impulse to a weapon actuator (not shown) facilitating a breech block (not shown) and a loading mechanism (not shown) to, for example, cycle the firearm 100 (FIG. 1).

In this example implementation, the gas bleed assembly 3 and the gas cylinder 12 are constructed from a single piece of material and are coupled to the barrel 1 via a collar 18. The collar 18 may be fitted (e.g., shrunk) onto an exterior surface 208 of the barrel 1. To ensure the position of the collar 18 relative to the barrel 1, the barrel 1 defines a step or offset 20 that is engaged by a surface 210 of the collar 18. Additionally, the collar 17 and the gas bleed assembly 13 are axially coupled in a circumferential direction to the barrel 1 via pins 22 (e.g., a spring pinning). The pins 22 may be any suitable pins 22 such as, for example, dowel pins, conical pins, etc. that draw the collar 18 downwards such that the gas channel 10 is adjacent the tap bore 8 to substantially prevent ammunition gasses from exhausting between the barrel 1 and the collar 18 during firing.

In the illustrated example, the piston 16 includes an elongated portion or auxiliary piston 16a that partially protrudes into an aperture or ventilation borehole 24 during a counter re-coil and/or in a rest position. In operation, after the pressure in the pressure chamber 14 increases to the predetermined level such that the piston 16 begins to move toward the rear of the firearm 100 (FIG. 1), the elongated portion 16a moves out of the aperture 24, which enables ammunition gases to exhaust to the atmosphere through the aperture 24 and a gas outlet or discharge nozzle 26. As the ammunition gasses exhaust to the atmosphere from the pressure chamber 14, the pressure in the pressure chamber 14 decreases, which reduces the resulting force acting against the piston 16 and the rod. By decreasing the pressure in the pressure chamber 14, the stress on the breech block and the loading mechanism also decrease.

A flow control apparatus or inlet piece 30 is positioned in a bore or aperture 32 defined by the gas bleed assembly 3. The aperture 32 is positioned approximately perpendicular relative to the bore axis 6 and intersects the gas channel 10. As illustrated in FIG. 2, the flow control apparatus 30 defines a first borehole 10a that has a first cross-sectional area and a second borehole 10b that has a second cross-sectional area. The first and second boreholes 10a and 10b intersect at approximately a 90 degree angle and may have different cross-sectional areas and/or diameters. While FIG. 2 depicts the boreholes 10a and 10b intersecting at approximately a 90 degree angle, the boreholes 10a and 10b may intersect at any other angle (e.g., a five degree angle, a ten degree angle, a fifteen degree angle, etc.).

As depicted in FIG. 2, the first borehole 10a is positioned to fluidly couple the tap bore 8 and the pressure chamber 14 and the second borehole 10b is positioned approximately parallel to the bore axis 6. However, if the flow control apparatus 30 is rotated approximately 90 degrees, the second borehole 10b fluidly couples the tap bore 8 and the pressure chamber 14 and the first borehole 10a is positioned approximately parallel to the bore axis 6. Changing which of the boreholes 10a or 10b fluidly couples the tap bore 8 and the pressure chamber 14, changes the amount of the ammunition gasses that flows from the barrel bore 4 to the pressure chamber 14 because the cross-sectional area of the first borehole 10a is different from the cross-sectional area of the second borehole 10b. The flow control apparatus 30 is designed to snuggly fit in the aperture 32 such that a plurality of first or second openings 214 or 216 of the boreholes 10a or 10b sealingly engage a surface 218 of the aperture 32 when the respective borehole 10a and 10b is not aligned with the tap bore 8.

In contrast to the examples described herein, if a marksman intends to use a silencer (not shown) with a known firearm that typically is provided with flash suppressor (e.g., similar to the flash suppressor 2 of FIG. 1), firing the firearm will result in the gas pressure in the barrel bore (e.g., similar to the barrel bore 4) and the pressure in the pressure chamber (e.g., similar to the pressure chamber 14) both being relatively higher as compared to when the firearm is fired with the flash suppressor, because a cross-sectional flow area of a channel that fluidly couples the pressure chamber and the barrel bore is configured to provide a particular firing cadence only in a single operation mode (e.g., firing the firearm with the flash suppressor). As discussed above, the increase in pressure accelerates the loading process and increases the force acting on the rod and the entire loading mechanism. In some instances, an increase in the firing cadence may result in the firearm jamming because the amount of time that is allotted to enable a cartridge (not shown) to move from a magazine (not shown) to a cartridge chamber (not shown) during reloading of the firearm is not adequate.

In contrast to known firearms, if a marksman intends to use a silencer (not shown) with the example firearm 100 that had previously been provided with the flash suppressor 2, the marksman may rotate the flow control apparatus 30 to enable the borehole 10a or 10b that has a relatively smaller cross-sectional flow area to fluidly couple the tap bore 8 and the pressure chamber 14 instead of the borehole 10a or 10b that has a relatively larger cross-sectional flow area. Utilizing the borehole 10a or 10b that has the relatively smaller cross-sectional flow area as opposed to the borehole 10a or 10b that has the relatively larger cross-sectional flow area, enables the firearm 100 to be utilized with the silencer, which increases the pressure in the barrel bore 4, without substantially effecting the pressure in the pressure chamber 14 and, thus, a desired firing cadence may be maintained. More generally, the examples described herein enable the firing speed of the firearm 100 implemented with the flash suppressor 2 to be substantially similar to the firing speed of the firearm 100 implemented with the silencer. Enabling a marksman to precisely and relatively quickly field adjust the cross-sectional flow area between the tap bore 8 and the pressure chamber 14 enables the firearm 100 to achieve a desired firing cadence in different operation modes and, thus, the versatility of the firearm is increased.

In some examples, if the firearm 100 is configured to fire NATO caliber 7.62 millimeter rounds, one of the boreholes 10a or 10b may have a diameter of approximately 1.7 millimeters (mm), which enables the firearm 100 to be fired with the flash suppressor 2 (e.g., a first operation mode) while maintaining a desired firing cadence. Additionally, the other of the boreholes 10a or 10b may have a diameter of approximately 1.2 mm to enable the firearm 100 to be fired with the silencer (e.g., a second operation mode) while maintaining a desired firing cadence. For other common calibers used with rifles, assault rifles or machine guns, the boreholes 10a and/or 10b may be between about 0.5 mm and 2 mm. However, the diameter and/or the cross-sectional area of the borehole 10a and/or 10b may vary depending on the type and size of the round and/or cartridge to be fired.

The flow control apparatus 30 is designed to be inserted and secured in the aperture 32 of the gas bleed assembly 3.

FIG. 7 depicts an enlarged view of the flow control apparatus 30. The flow control apparatus 30 includes a head or end 34 that includes an indicator or tab 36. In operation, the position of the indicator 36 relative to the firearm 100 may indicate the position of the respective borehole 10a or 10b relative to the tap bore 8 and the gas channel 10.

Turning to FIG. 3, to enable the flow control apparatus 30 to be relatively easily rotated in the aperture 32, a surface 302 of the head 34 defines a hexagonal profile 38 (e.g., an opening) and a slot 40 (e.g., an opening). For example, a coin (not shown) may be inserted into the slot 40 and turned to rotate the flow control apparatus 30 such that the first borehole 10a fluidly couples the tap bore 8 and the pressure chamber 14. Alternatively, a tool (not shown) may be inserted into the hexagonal profile 38 and turned to rotate the flow control apparatus 30 such that the second borehole 10b fluidly couples the tap bore 8 and the pressure chamber 14. While FIG. 3 depicts the head 34 having a hexagonal profile 38, the head 34 may define any other profile and/or opening that corresponds to any suitable tool.

Turning to FIG. 7, the openings 214 and 216 of the boreholes 10a and 10b are positioned along an elongated member or cylindrical shank 42 of the flow control apparatus 30. To secure and/or retain the flow control apparatus 30 in the aperture 32, a groove or indentation 44 is defined toward an end 702 of the elongated member 42 that receives at least a portion of a locking member or locking device 46 (FIG. 6). The locking member 46 is biased via a spring 48 that urges an end 52 of the locking member 46 toward the groove 44. A stop or locking pin 50 ensures that the spring 48 maintains its position in a bore 49 and that the spring 48 urges the locking member 46 toward the flow control apparatus 30.

The groove 44 includes a plurality of side walls, radial sides or lateral walls 54 and 56 between which the end of the locking member 46 may be positioned to secure the flow control apparatus 30 and to substantially ensure that the flow control apparatus 30 is not unintentionally removed from the aperture 32. The side walls 54 and 56 are connected via connecting walls, corner arcs or lateral walls 58 and 60. The position of the connecting walls 58 and 60 relative to the borehole 10a and 10b ensures that when the end 52 of the locking member 46 engages either of the connecting walls 58 and 60, one of the boreholes 10a or 10b is aligned with the tap bore 8. More generally, the connecting walls 58 and 60 form a stopper to substantially restrict the movement of the locking member 46 in a circumferential direction.

Additionally, the groove 44 includes a first surface 62 and a second surface 64, which are separated by an edge 63. For example, if the first borehole 10a initially fluidly couples the tap bore 8 and the pressure chamber 14, the end 52 of the locking member 46 may engage the second surface 64. As the flow control apparatus 30 is rotated to enable the second borehole 10b to fluidly couple the tap bore 8 and the pressure chamber 14, a surface 66 of the locking member 46 follows the second surface 64 toward the edge 63. Once the surface 66 of the locking member 46 engages the edge 63, the locking member 46 is depressed toward the locking pin 50 against a force of the spring 48. As the flow control apparatus 30 is further rotated, the force of the spring 48 urges the locking member 46 toward the groove 44 and, thus, the flow control apparatus 30 may be urged to rotate. As the flow control member 30 is rotated, the surface 66 of the locking member 46 follows the first surface 62 until the end 52 engages the connecting wall 60 at which point the second borehole 10b is aligned to fluidly couple the tap bore 8 and the pressure chamber 14.

Turning to FIG. 4, to enable the flow control apparatus 30 to be removed from the aperture 32, the firearm 100 is provided with a lever or actuating pin 68 that is positioned in a channel 70 such that the lever 68 is externally accessible. The lever 68 is operatively coupled to the locking member 46 such that by moving the lever 68 toward the rear of the firearm 100 (FIG. 1), the locking member 46 is moved away from the groove 44. Once the locking member 46 is completely removed from the groove 44, the flow control apparatus 30 may be removed from (e.g., pushed out of) the aperture 32. To prevent the locking member 46 from extending too far into the aperture 32 and/or to prevent the locking member 46 from being misplaced or lost, the locking member 46 includes a shoulder 72 that engages a step 73 after the flow control apparatus 30 is removed from the aperture 32.

While the flow control apparatus 30 is depicted as including the first borehole 10a and the second borehole 10b, the flow control apparatus 30 may include any number of boreholes (e.g., 1, 2, 3, 4, 5, etc.). In such examples, the groove 44 of the flow control apparatus 30 may include a corresponding number of surfaces to be engaged by the surface 66 on the end 52 of the locking member 46. While not shown, in other examples, the flow control apparatus 30 may define a single borehole configured to be used with a particular operation mode. In such examples, a marksman may have a plurality of different flow control apparatus 30 each having a borehole having a different cross-sectional flow area. In operation, depending on the operation mode, different flow control apparatus 30 having different cross-sectional flow areas may be interchanged in the aperture 32.

In other examples, the boreholes 10a and 10b may be aligned along an axis 704 of the elongated member 42. To align the different boreholes 10a or 10b with the tap bore 8, the flow control apparatus 30 may be moved into or out of the aperture 32. In this example, the flow control apparatus 30 may be configured as a slider and be provided with grooves (not shown), which are engaged by the locking member 46 to secure the flow control apparatus 30 relative to the aperture 32 once the desired borehole 10a or 10b fluidly couples the tap bore 8 and the pressure chamber 14.

The examples described herein enable the cross-sectional flow area to be adjusted for the firearm 100 via the flow control apparatus 30. Specifically, the flow control apparatus 30 enables the cross-sectional flow area to be tailored to a particular operation mode such as, for example, firing the firearm 100 with the flash suppressor 2, firing the firearm 100 with a silencer, firing the firearm 100 with a first type of ammunition (e.g., ammunition having a smaller propellant charge, a smaller bullet mass, etc.) and/or firing the firearm 100 with a second type of ammunition (e.g., ammunition having a larger propellant charge, a higher bullet mass, etc.).

The flow control apparatus 30 may be tailored to a particular type of firearm and/or a particular application. Additionally, the flow control apparatus 30 may be relatively easily interchanged without additional necessary adjustments being performed on the firearm 100.

As discussed above, the flow control apparatus 30 is insertable and removable from the aperture 32. Additionally, once the flow control apparatus 30 is inserted into the aperture 32, the flow control apparatus 30 may be adjusted (e.g., rotated or moved) to change the cross-sectional flow area between the tap bore 8 and the pressure chamber 14. The design of the flow control apparatus 30 may be relatively easily produced and may be relatively easily implemented in different types of firearms and/or firearms configured to fire different size calibers.

As described above, the flow control apparatus 30 defines a plurality of boreholes 10a and 10b each having a cross sectional flow area that corresponds to a different operation mode. Generally, the flow control apparatus 30 enables the operation mode of the firearm 100 to be switched back and forth. In operation, the operation mode of the firearm 100 is changed by rotating and/or moving the flow control apparatus 30 relative to the aperture 32.

As discussed above, the position of the flow control apparatus 30 may be secured to ensure that one of the boreholes 10a or 10b fluidly couples the tap bore 8 and the pressure chamber 14.

As described above, the locking member 46 is urged toward the groove 44 via the spring 48. The groove 44 includes the side walls 54 and 56 and the connecting walls 58 and 60. The interaction between the locking member 46 and the groove 44 substantially prevents the locking member 46 from rotating beyond a certain point because the end 52 of the locking member 46 engages either of the connecting walls 58 and 60. Additionally, the interaction between the locking member 46 and the groove 44 substantially ensures that the surface 66 on the end 52 of the locking member 46 engages either the first surface 62 or the second surface 64 when one of the boreholes 10a or 10b fluidly couples the tap bore 8 and the pressure chamber 14. Further, the interaction between the locking member 46 and the groove 44 substantially prevents the flow control apparatus 30 from being unintentionally removed from the aperture 32 because of the interaction between the end 52 and the side walls 54 and 56 and/or the connecting walls 58 and 60. The groove 44 may be produced, manufactured and/or fabricated via any suitable method such as, for example, turning, milling, grinding, precision casting, injection molding, etc.

As discussed above, the flow control apparatus 30 is provided with the indicator 36 that enables a marksman to feel and/or visually identify the position of the indicator 36 and, thus, which of the boreholes 10a or 10b is aligned with the tap bore 8 and/or the position of the flow control apparatus 30 relative to the aperture 32. Readily identifying the position of the flow control apparatus 30 relative to the aperture 32 via touch and/or visual verification, enables the marksman to quickly determine if the firearm 100 is in the proper operation mode.

As described above, the surface 302 of the head 34 may include the hexagonal profile 38 and/or the slot 40, which are to receive a tool to more easily enable the flow control apparatus 30 to be adjusted.

Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Claims

1. A field adjustable gas bleed assembly for use with a firearm having a barrel, comprising:

a gas cylinder that defines a pressure chamber to be fluidly coupled to a bore of a barrel, wherein the gas cylinder is substantially fixed relative to the barrel; and

a fluid control apparatus to control a flow rate of fluid between the pressure chamber and the barrel, wherein the fluid control apparatus is adjustable between a first operation mode and a second operation mode that is different from the first operation mode, wherein the fluid control apparatus comprises: a first borehole having a first cross-sectional area, wherein the first borehole is associated with the first operation mode; and a second borehole having a second cross-sectional area different from the first cross-sectional area, wherein the second borehole is associated with a second operation mode.

2. The gas bleed assembly as defined in claim 1, wherein the first operation mode is associated with firing the firearm with a flash suppressor, which causes a first gas pressure in the bore of the barrel and wherein the second operation mode is associated with firing the firearm with a silencer, which causes a second gas pressure in the bore of the barrel.

3. The gas bleed assembly as defined in claim 1, wherein the first operation mode is associated with firing the firearm with a first type of ammunition and the second operation mode is associated with firing the firearm with a second type of ammunition.

4. The gas bleed assembly as defined in claim 1, wherein the gas bleed assembly defines an aperture in which the fluid control apparatus is to be inserted.

5. The gas bleed assembly as defined in claim 4, wherein the fluid control apparatus is rotatable within the aperture between the first operation mode and the second operation mode.

6. The gas bleed assembly as defined in claim 5, wherein when the fluid control apparatus is positioned in the first operation mode, the first borehole fluidly couples the pressure chamber and the bore of the barrel and second openings of the second borehole sealingly engage a surface of the aperture and wherein when the fluid control apparatus is positioned in the second operation mode, the second borehole fluidly couples the pressure chamber and the bore of the barrel and first openings of the first borehole sealingly engage the surface of the aperture.

7. The gas bleed assembly as defined in claim 5, wherein the fluid control apparatus is lockable in either the first operation mode or the second operation mode.

8. The gas bleed assembly as defined in claim 7, wherein the fluid control apparatus includes an elongated member that defines a groove to receive a biased locking member, wherein the groove includes a plurality of lateral walls to retain the locking member within the groove.

9. The gas bleed assembly as defined in claim 8, wherein the groove further includes a first surface and a second surface that are separated by an edge and wherein an end of the locking member is to follow at least the first surface or the second surface as the fluid control apparatus is rotated between the first operation mode and the second operation mode.

10. The gas bleed assembly as defined in claim 8, wherein the plurality of lateral walls comprise a plurality of side walls and a plurality of connecting walls that connect the plurality of side walls.

11. The gas bleed assembly as defined in claim 10, wherein when an end of the locking member engages one of the connecting walls the fluid control apparatus is positioned in the first operation mode and wherein when the end of the locking member engages another one of the connecting walls the fluid control apparatus is positioned in the second operation mode.

12. The gas bleed assembly as defined in claim 1, wherein the fluid control apparatus includes an indicator to indicate whether the fluid control apparatus is positioned in the first operation mode or the second operation mode.

13. The gas bleed assembly as defined in claim 1, wherein the fluid control apparatus includes a head that defines an opening to receive a tool to move the fluid control apparatus between the first operation mode and the second operation mode.

14. A fluid control apparatus to be inserted in an aperture of a gas bleed assembly of a firearm to control a flow rate of fluid between a pressure chamber and a bore of a barrel, comprising:

an elongated member, wherein the elongated member defines: a first borehole having a first cross-sectional area, wherein the first borehole is associated with a first operation mode; and a second borehole having a second cross-sectional area different from the first cross-sectional area, wherein the second borehole is associated with a second operation mode;

wherein when the fluid control apparatus is positioned in the first operation mode, the first borehole fluidly couples the pressure chamber and the bore of the barrel and second openings of the second borehole sealingly engage a surface of the aperture and wherein when the fluid control apparatus is positioned in the second operation mode, the second borehole fluidly couples the pressure chamber and the bore of the barrel and first openings of the first borehole sealingly engage the surface of the aperture.

15. The fluid control apparatus as defined in claim 14, wherein the fluid control apparatus is rotatable within the aperture between the first operation mode and the second operation mode.

16. The fluid control apparatus as defined in claim 15, wherein the elongated member defines a groove to receive a biased locking member of the gas bleed assembly, wherein the groove includes a plurality of lateral walls to retain the locking member within the groove.

17. The fluid control apparatus as defined in claim 16, wherein the groove further includes a first surface and a second surface that are separated by an edge and wherein an end of the locking member is to follow at least the first surface or the second surface as the fluid control apparatus is rotated between the first operation mode and the second operation mode.

18. The fluid control apparatus as defined in claim 16, wherein the plurality of lateral walls comprise a plurality of side walls and a plurality of connecting walls that connect the plurality of side walls.

19. The fluid control apparatus as defined in claim 18, wherein when an end of the locking member engages one of the connecting walls the fluid control apparatus is positioned in the first operation mode and wherein when the end of the locking member engages another one of the connecting walls the fluid control apparatus is positioned in the second operation mode.

20. The fluid control apparatus as defined in claim 14, wherein the fluid control apparatus includes an indicator to indicate whether the fluid control apparatus is positioned in the first operation mode or the second operation mode.